I have flown in since 1981.
Camping in the North 40 affords you access to the shopping and restaurants north and west of the airport.
When my wife and kids came with me between 2001 and 2006, I would go to the grocery store during the end of the airshow and pick up fresh meat, frozen veggies and boil-a-bag rice. I brought a small gas grill with me and cooked dinner each night.
If you camp in the South 40 (alias North Fond du Lac), you will have quite a trek to the camp store for your vittles. I don't recommend hauling your stays worth of food and bottled water with you. It takes up too much space and weight.
Light weight fleece sleeping bags with a down throw provide comfortable sleeping, are light weight and pack small.
Most important is a tent with full bathtub floor, and a full length rain fly. Include extra stakes and rope for guying. Those of us who are regulars can attest to sad moments we have witnessed the experience of campers with less than adequate equipment.
Use paper plates and plastic utensils, throw them away after each meal. A pot, maybe a skillet, a small polypropolene cutting board, a small serrated kitchen knife, a serving spoon, a spatula and a small propane or Coleman fuel stove are all the cooking utensils you would need to bring with you.
For towels, the Sham-Wow synthetic things work well. They dry fast and you only need a 24"x24" piece for each person.
Try to avoid cotton clothing. Buy some inexpensive polyester hiking pants, polyester underwear, polyester t-shirts and polyester hiking socks. You can rinse/wash them out each day when you shower. Polyester wicks persperation away from the body so it can evaporate, keeping you cool. If it does get wet in a rainstorm, you body heat will dry it out. If you need it, there is a laundrymat at the northwest corner of the airport just outside the gate.